Imperial College London
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ProfessorDarioFarina

Faculty of Engineering, Department of Bioengineering

Chair in Neurorehabilitation Engineering
 
 
 
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Contact

 

+44 (0)20 7594 1387d.farina Website

 
 
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Location

 

RSM 4.15Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Levine:2022:10.1101/2022.11.11.516183,
author = {Levine, J and Avrillon, S and Farina, D and Hug, F and Pons, JL},
doi = {10.1101/2022.11.11.516183},
title = {Two motor neuron synergies, invariant across ankle joint angles, activate the triceps surae during plantarflexion},
url = {http://dx.doi.org/10.1101/2022.11.11.516183},
year = {2022}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - <jats:title>Abstract</jats:title><jats:p>Recent studies have suggested that the nervous system generates movements by controlling groups of motor neurons (synergies) that do not always align with muscle anatomy. In this study, we determined whether these synergies are robust across tasks with different mechanical constraints. We identified motor neuron synergies using principal component analysis (PCA) and cross-correlations between smoothed discharge rates of motor neurons. In Part 1, we used simulations to validate these methods. The results suggested that PCA can accurately identify the number of common inputs and their distribution across active motor neurons. Moreover, the results confirmed that cross-correlation can separate pairs of motor neurons that receive common inputs from those that do not receive common inputs. In Part 2, sixteen individuals performed plantarflexion at three ankle angles while we recorded electromyographic signals from the gastrocnemius lateralis (GL) and medialis (GM) and the soleus (SOL) with grids of surface electrodes. PCA revealed two motor neuron synergies. These motor neuron synergies were relatively stable with no significant differences in the distribution of motor neuron weights across ankle angles (p=0.62). When the cross-correlation was calculated for pairs of motor units tracked across ankle angles, we observed that only 13.0% of pairs of motor units from GL and GM exhibited significant correlations of their smoothed discharge rates across angles, confirming the low level of common inputs between these muscles. Overall, these results highlight the modularity of movement control at the motor neuron level, suggesting a sensible reduction of computational resources for movement control.</jats:p><jats:sec><jats:title>Key points summary</jats:title><jats:list list-type="bullet"><jats:list-item><jats:p>The central nervous system may generate movements by activ
AU  - Levine,J
AU  - Avrillon,S
AU  - Farina,D
AU  - Hug,F
AU  - Pons,JL
DO  - 10.1101/2022.11.11.516183
PY  - 2022///
TI  - Two motor neuron synergies, invariant across ankle joint angles, activate the triceps surae during plantarflexion
UR  - http://dx.doi.org/10.1101/2022.11.11.516183
ER  -
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